The present invention relates to a novel polysaccharide isolated from Panax ginseng having the hematopoietic, myeloprotecting, antitumor immune cells generating and radiosensitizing activities. The present invention also includes the preparation method of the polysaccharide from Panax ginseng and the pharmaceutical composition for enhancing the hematopoietic, myeloprotecting, antitumor immune cells generating, and radiosensitizing activities.
In detail, the polysaccharide isolated from Panax ginseng of the present invention is obtained by the preparation method comprising the steps of: i) obtaining the residue using methanol, ii) extracting and obtaining the water soluble fraction using distilled water, iii) obtaining the precipitate using 40% of ethanol, and iv) obtaining the polysaccharide using the dialysis membrane v) obtaining the 6 fractions by sephacryl S-500 gel chromatography vi) purification of polysaccharide by DEAE-sephadex A-50 chromatography which is composed of 6 kinds of polysaccharide being molecular weight 1,800,000xcx9c2,200,000, 1,350,000xcx9c1,650,000, 620,000xcx9c780,000, 105,000xcx9c130,000, 23,000xcx9c27,000, 5,000xcx9c6,000 dalton existing 11.4xcx9c13.4:3.6xcx9c4.2:4.5xcx9c5.1:0.7xcx9c0.9:40.1xcx9c48.1:31.0xcx9c37.0 ratio, mainly consists of xcex1(1xe2x86x926) linked D-glucopyranose units and has branches linked in part at the C-3 position.
Many polysaccharides extracted from Panax ginseng had been reported before the completement of the present invention. Followings are well-known reports in this regard.
Panaxan, one of glycans consisting of D-glucose, was disclosed as active ingredient for declining the blood sugar level [Konno C. et al., Isolation and hypoglycemic activity of Panaxan A.B.C.D. and E glycans of Panax ginseng roots, Planta Medica 50 pp 434xcx9c436, 1984]. The polysaccharides comprising galacturonic acid, glucose, arabinose, mannose and galactose was disclosed as the material having anti-complementary effect [Gao Q., Kiyohara H. et al., Chemical properties and anti-complementary activities of polysaccharide fractions from roots and leaves of Panax ginseng, Planta Medica 55 pp 9xcx9c12, 1989]. Further, the polysaccharide from Panax ginseng was reported to have antitumor or bacterial resistance activities [Japanese Laying-Open Patent No. 1986-18722 A1].
Even though such polysaccharides described above are all extracted from Panax ginseng, the components of such polysaccharides are different from those of the present invention. Further, polysaccharide extracted from Panax ginseng has never been disclosed as a material for enhancing the hematopoietic, myeloprotecting, antitumor immune cells generating and radiosensitizing activities.
On the other hand, the efficacious materials from Panax ginseng belong to the saponin derivatives, which have different molecular structure compared to the polysaccharide of the present invention.
xcex2-Glucan separated from yeast cell wall has been known to have the hematopoietic activity, but has different molecular structure from the polysaccharide of the present invention. Further, the powder of OK-432, which is prepared by the heat treatment to the cell line of Streptococcus pyrogenes Su, together with Lentinan extracted from Lentinus edodes, have been disclosed as biological response modifiers(BRMs), but also have xcex2-glucan structure.
The present invention has been completed by the purification and isolation of polysaccharide having the activities of promoting the growth of hematopoietic cells, myeloprotecting, antitumor immune cells generating, and radiosensitizing tumor cells from the roots of Panax ginseng. 
The object of the present invention is to provide a polysaccharide composition having the hematopoietic, myeldoprotecting, antitumor immune cell generating, and radiosensitizing activities purified from the roots of Panax ginseng prepared by the steps of:
i) obtaining the residue by extracting 1 wt part of ginseng roots with 2xcx9c4 wt part of methanol;
ii) extracting and obtaining the water soluble fraction from the residue in step i) using 3xcx9c5 wt part of distilled water;
iii) freeze-drying the obtained water soluble fraction in step ii);
iv) obtaining the inner fraction using the dialysis membrane after obtaining the insoluble fraction to the 40% of ethanol from freeze-dried fraction in step iii);
v) obtaining 6 fractions by sephacryl S-500 gel chromatography; and
vi) purifying the polysaccharide by DEAE-sephadex A-50 chromatography.
Another object of the present invention is to provide a polysaccharide which is composed of 6 kinds of polysaccharide being molecular weight 1,800,000xcx9c2,200,000, 1,350,000xcx9c1,650,000, 620,000xcx9c780,000, 105,000xcx9c130,000, 23,000xcx9c27,000, 5,000xcx9c6,000 dalton existing 11.4xcx9c13.4:3.6xcx9c4.2:4.5xcx9c5.1:0.7xcx9c0.9:40.1xcx9c48.1:31.0xcx9c37.0 ratio, consists of xcex1(1xe2x86x926) linked D-glucopyranose units with partly xcex1(1xe2x86x923) linked branches.
Also, a polysaccharide comprises more than 98.5% amount of carbohydrate and less than 1.0% amount of protein by quantitative determination.
The further object of the present invention is to provide a pharmaceutical composition having the polysaccharide for enhancing the hematopoietic, myeloprotecting, antitumor immune cells generating, and radiosensitizing activities.